Process for breaking petroleum emulsions



Patented Jan. 27, 1953 PROCESS FOR BREAKING PETROLEUM EMULSIONS MelvinDe Groote, University City, Mo., assignor to Petrolite Corporation, acorporation of Dela- Wall'B No Drawing. Application May 14, 1951,

Serial No. 226,336

11 Claims.

The present invention is a continuation-inpart of my co-pendingapplications Serial Nos. 104,801, filed July 14, 1949 (now Patent No.2,552,528, granted May 15, 1951), 109,619, filed August 10, 1949 (nowPatent 2,552,531, granted May 15, 1951), and 107,381, filed July 28,1949 (now Patent 2,552,530, granted May 15, 1951).

This invention relates to petroleum emulsions of the water-in-oil type,that are commonl referred to as cut oil, "roily oil, emulsified oil,etc., and which comprise fine droplets of naturally-occurring waters orbrines dispersed in a more or less permanent state throughout the oilwhich constitutes the continuous phase of the emulsion.

One object of my invention is to provide a novel process for breaking orresolving emulsions of the kind referred to. Another object of myinvention is to provide an economical and rapid process for separatingemulsions which have been prepared under controlled conditions frommineral oil, such as crude oil and relatively soft Waters or weakbrines. Controlled emulsification and subsequent demulsification, underthe conditions just mentioned, are of significant value in removingimpurities, particularly inorganic salts from pipeline oil.

Demulsification, as contemplated in the present application, includesthe preventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion, in absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractionalester obtained from a polycarboxy acid and a polyhydroxylated materialobtained by the oxypropylation of a polyamino reactant.

More specifically, the present process involves the use of ademulsifying agent which is an acylation product of a polycarboxy acidwith a compound derived, in turn, by the oxypropylation or" a phenylenediamine, or an equivalent diamine, as hereinafter specified, having fourterminal hydroxyl radicals or the equivalent, i. e., labile hydrogenatoms susceptible to oxyalkylation. Indeed, as pointed out hereinafter,the diamine derivative need only have a plurality of reactive hydrogenatoms, i. e., 2 or more.

The most suitable raw material is a phenylene diamine as such, andparticularly metaphenylene diamine, on account of its cost, or suchdiamine after treatment with several moles of ethylene oxide or glycide,or a combination of the two, and particularly a phenylene-diamine afterbeing treated with one to 4 or even 5 or 6 moles of ethylene oxide. Theinitial diamino compound must be characterized by ((1) Having 2 aminonitrogen atoms;

(b) Free from any radical having 8 or more carbon atoms in anuninterrupted group;

(0) Must be water-soluble;

(d) Have a plurality of reactive hydrogen atoms, preferably at least 3or 4; and

(6) Must have a molecular weight not over 800.

The oxypropylated derivatives of such diamines which are reactive withpolycarboxy acids to produce compounds used in accordance with thepresent invention, must have a molecular Weight within the range of 2000to 30,000, must be waterinsoluble and kerosene-soluble, must have aratio of propylene oxide to reactive hydrogen atoms of the diaminocompound in the range of 7 to 70, and the diamino compound mustrepresent not more than 20% by weight of the oxypropylated product, theratio and molecular weights specified being on a statistical basis andbased on an assumption of complete reaction between the diamino compoundand the propylene oxide.

When forming the acylation products, the polycarboxy acid is used in themolar ratio of one mole of polycarboxy acid for each reactive hydrogenof the oxypropylated diamino compound.

For reasons which will be pointed out, I believe the products areessentially fractional esters, but may to some extent have an amidestructure and in addition, may also be in the form of ester salts. Forthis reason, they are referred to above as acylation products, and forthis reason in the claims the products are referred to as being selectedfrom the class consisting of acidic fractional esters, acidic estersalts, and acidic amido derivatives.

Needless to say, the most readily available reactant, to wit,metaphenylene diamine,'has four reactive hydrogen atoms and this wouldstill be true after reaction with ethylene oxide, for instance, 1 to 4moles of ethylene oxide. However,

reaction with glycide would provide as many as 8 reactive hydrogenatoms, provided that the molal ratio was 4 to 1, i. e., 4 moles ofglycide for one mole of diamine. On the other hand, if metaphenylenediamine were treated with an alkylating agent so as to introduce analkyl radical such as methyl, ethyl, propyl, butyl, hexyl, heptyl, orthe like, or an aryl radical such as a phenyl radical, then and in thatevent, the number of reactive hydrogen atoms might be decreasedit'o asfew as two andzstill. beacceptable for the instant purpose.

For obvious reasons, my choice is as follows:

(a) The use of metaphenylene diamine rather: than any other otherphenylene diamine, primarily because this is the cheapestisomena'vailable;

(b) Use of metaphenylene diamine aftertreatement with 1 to 5 moles of."ethylene. oxide, although a modestly increased amount of ethylene oxidecan be used in light of what issaid hereinafter; or

(c) The use of a derivative obtained from metaphenylene diamine afterreaction with glycide, or a mixture of ethylene oxide and glycide.

since: reaction. of metaphenylene diamine with propylene oxide isinvariably involved, and since this o'xyalkylation step'is substantiallythe same as the use-of ethylene oxide or glycide, for purpose ofbrevity, future reference will be made to metaphenylene diamine asillustrating a procedure', regardless of what particular reactant issele'cte'd. It is not necessary to point out, of course, that thesubstituted phenylenedi'amine, i. e., where-an alkyl, alicyclic, aryl oralkyl group has' b'een: introduced, can be subjected similarly toreaction with ethylene oxide, glycide, or a combination of the: two.

I also want to point? out it is: immaterial whether the'i'nitialoxypropylation step involves hydrogen attached to oxygen or" hydrogenattached to-nitrogen. Thgessential requirement is tl'iat it be" a labileor reactive hydrogen atom. Any substituent radical present must, ofcourse, have less than 8 uninterrupted carbon atoms; in a: single group.

Considerable work' has been conducted" on the oxypropylation of highmolal compounds, or at least oxypropylation of low molal compoundshaving a multiplicity of points of reaction to yield high molal;compounds. The starting materials: may be fairly simple, such asethylene glycol orrpropylene glycol; 01: they may be amines which areessentially derivatives of ammonia, or compounds having: t or. morepoints. of reaction suclfc as ethylene? diamine, propylene diamine,higher polyamin'es, diglycerol, sorbitol, etc. In other instances;amides and diamides have been employed.

Briefly stated, and this at the most can be onlya summarizatiomwhen themolecular weight duatooxypropylation goes beyond 2,000 and frequentlyless, there is a wide diiference between the-theoretical molecularweight, based on completeness of' reaction and the molecular weight asdetermined by a' hydroxyl number, or the equivalent. Unfortunately, thehigher polyoxypropylenephenylenediamines have not been examined; and theresults obtained in the case of phenylenediamine still suggest that thesame forces are in effect as in these other comparable oxypropylations.For this reason, what is said hereinafter in the text immediatelyfollowing, considers some of these f'actors, particularly from thestandpoint of amides, higher polyalkylene 4 amines, etc. Such data areincluded, for the reason that this presentation appears the bestavailable to throw some light on the oxypropylation of the hereindescribed reactant, to wit, a phenylenediamine.

Reference to the products as fractional esters, may be and probably isan oversimplification, for reasons which are obvious on furtherexamination. It is pointed out subsequently that, prior toesterification, the alkaline catalyst can be removed by addition of.hydrochloric.- acid. Actually, the amount of hydrochloric acid added isusually suflicient and one can deliberately employ enough acid, not onlyto neutralize the alkaline catalyst, but. also to neutralize the aminonitrogen atom or convert it into a salt. Stated another way, a trivalentnitrogen atom is converted intoa pentavalent nitrogen atom, i. e., achange involvingan electrovalency indicated as follows:

ill

wherein HX represents any strong acid or fairly strong acid such ashydrochloric-acid, nitric acid, sulfuric acid, a sulfonic acid, etc., inwhich 1-! represents the acidic hydrogen atom and X'represents theanion. Without attempting to complicatethe subsequent descriptionfurther, it is obvious then thatone-might-have esters orone mightconvert the esters into ester salts, as described. Likewise; anotherpossibility is that, under certain. conditions, one could obtain amides.The explanation of this latter fact resides in this observation. In thecase of an amide; such as'acetamide', there is always a question as towhether or notoxypropylation involves both amido nitrogen atoms solastoiobtainahundred percent yield of the. dihydroxylated compound. Thereis' someevidence to at least some degree, that a monohydroxylatedcompoundis obtained, under some circumstances, with one amido hydrogenatom remaining without change.

Another explanation which has sometimes appeared in the oxypropylationof nitrogen-containing compounds, particularly such as acetamide, isthat the molecule appears to decompose under conditions of analysis andunsaturation seems to appear simultaneously; One suggestion has. been.that. one hydroxyl is. lost by dehydration andthat this ultimatelycauses a break in the molecule in such. a way that. two. new hydroxylsare formed. This is. shown, after a fashion, in a highly idealizedmanner in the following way:

In the above formulas the large X is obviously not intended to signifyanything except the central part of a large molecule, whereas, as far asa speculative explanation is concerned, one need only consider theterminal radicals, as shown. Such suggestion is of interest only becauseit may be a possible explanation of how an increase in hydroxyl valuedoes take place which could be interpreted as a decrease in molecularweight. This matter is considered subsequently in the final paragraphsof Part 2.

In the case of higher polyamines, there is evidence that all theavailable hydrogen atoms are not necessarily attacked, at least undercomparatively modest oxypropylation conditions, particularly whenoxypropylation proceeds at low temperature, as herein described, forinstance, about the boiling point of water. For instance, in the case ofdiethylene triamine there is some evidence that one terminal hydrogenatom only in each of the two end groups is first attacked by propyleneoxide and then the hydrogen atom attached to the central nitrogen atomis attacked. It is quite possible that three long propylene oxide chainsare built up before the two remaining hydrogens are attacked and perhapsnot attacked at all. This, of course, depends upon the conditions ofoxypropylation. However, analytical procedure is not entirelysatsifactory, in some instances, in difierentiating between a reactivehydrogen atom attached to nitrogen and a reactive hydrogen atom attachedto oxygen;

In the case of triethylenetetramine the same situation seems to follow.One hydrogen atom on the two terminal-groups is first attacked and thenthe two hydrogen atoms on the two intermediate nitrogen atoms. Thus,four chains tend to build up and perhaps finally, if at all, theremaining two hydrogen atoms attached to the two terminal groups areattacked. In the case of tetraethylenepentamine the same approach seemsto hold. One hydrogen atom on each of the terminal groups is attackedfirst, then the three hydrogen atoms attached to the three intermediatenitrogen atoms, and then finally, if

at all, depending upon conditions of oxypropylation, the two remainingterminal hydrogen atoms are attacked.

If this is the case, it is purely a matter of speculation at the moment,because apparently there is no data which determines the mattercompletely under all conditions of manufacture, and one has a situationsomewhat comparable to the acylation of monoethanolamine ordiethanolamine, i. e., acylation can take place involving either thehydrogen atom attached to oxygen or the hydrogen atom attached tonitrogen.

It is unnecessary to add that What has been said in regard topolyethyleneamines, including ethylenediamine, also applies topolypropyleneamines, including propylenediamine.

As far as the herein described compounds are concerned, it would beabsolutely immaterial, except that one would have, in part, a compoundwhich might be the fractional ester and might also represent an amide inwhich only one carboxyl radical of a polycarboxylated reactant wasinvolved. By and large, it is believed that the materials obtained areobviously fractional esters, for reasons which are apparent in light ofwhat has been said and in light of what appears hereinafter.

For convenience, what is said hereafter will be divided into four parts:

Part 1 is concerned with the preparation of the oxypropylationderivatives of phenylenediamine or equivalent initial reactants;

Part 2 is concerned with the preparation of the esters from theoxypropylated derivatives;

Part 3 is concerned with the nature of the oxypropylation derivativesinsofar that a cogeneric mixture is invariably obtained; and

Part 4 is concerned with the use of the products herein described asdemulsifiers for breaking water-in-oil emulsions.

PART 1 For a number of well known reasons equipment, whether laboratorysize, semi-pilot plant size, pilot plant size, or large scale size, isnot as a rule designed for a particular alkylene oxide. Invariably andinevitably, however, or particularly in the case of laboratory equipmentand pilot plant size, the design is such as to use any of thecustomarily available alkylene oxides, i. e., ethylene oxide, proplyeneoxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. Inthe subsequent description of the equipment it be comes obvious that itis adapted for oxyethylation as well as oxypropylation.

Oxyp-ropylations are conducted under a wide variety of conditions, notonly in regard to presence or absence of catalyst, and the kind ofcatayst, but also in regard to the time of reaction, temperature ofreaction, speed of reaction, pressure during reaction, etc. Forinstance, oxyalkylations can be conducted at temperature up toapproximately 200 C. with pressures in about the same range up to about200 pounds per square inch. They can be conducted also at temperaturesapproximating the boiling point of water or slightly above, as, forexample, to 0'. Under such circumstances, the pressure will be less than30 pounds per square inch unless some special procedure is employed, asis sometimes the case, to wit, keeping an atmosphere of inert gas suchas nitrogen in the vessel during the reaction. Such low-temperature-lowreaction rate oxypropylations have been described very completely in U.S. Patent No. 2,448,664 to H. R. Fife et al, dated September '7, 1948.Low-temperature-low-pressure oxypropylations are particularly desirablewhere the compound being subjected to oxypropylation contains one, two,or three points of reaction only, such as monohydric alcohols, glycolsand triols.

The initial reactants in the instant application contain at least 2reactive hydrogens, and for this reason, there is possibly lessadvantage in using low-temperatureoxypropylation, rather than hightemperature oxypropylation. However, the reactions do not go too slowly,and this particular procedure was used in the subsequent examples.

Since low-pressure-low-temperature-low-reaction speed oxypropylationsrequire considerable time, for instance, 1 to 7 days of 24 hours each tocomplete the reaction, they are conducted as a rule whether on alaboratory scale, pilot plant scale, or large scale, so as to operateautomatically. The prior figure of seven days applies especially tolarge-scale operations. I have used conventional equipment with twoadded automatic features:

(a) A solenoid-controlled valve which shuts off the propylene oxide inevent that the temperature gets outside a predetermined and set range,for instance, 95 to 120 0.; and

(b) Another solenoid valve which shuts off the; propylene oxide (or forthat matter ethylene oxide if it is being used) if the pressure getsbeyond a predetermined range, such as 25 to 35 pounds. Otherwise, theequipment is substantially the same as is commonly employed for thispurpose, where the pressure of reaction is higher, speed of reaction ishigher, and time of reaction is much shorter. In such instances suchautomatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularlyadvantageous to use laboratory equipment or pilot plant which isdesigned to permit continuous oxyalkylation, whether it beoxypropylation or oxyethylation. With certain obvious changes, theequipment can be used also to permit oxyalkylation involving the use ofglycide where no pressure is involved except the vapor pressure of asolvent, if any, which may have been used as a diluent.

As previously pointed out, the method of using propylene oxide is thesame as ethylene oxide. This point is emphasized only for the reasonthat the: apparatus is so designed and constructed as to use eitheroxide.

The oxypropylation procedure employed in the preparation of theoxyalkylated derivatives has been uniformly the same, particularly inlight of the fact that a continuous, automatically-controlled procedurewas employed. In this procedure the autoclave was a conventionalautoclave made of stainless steel and having a capacity of approximatelygallons and a working pressure of one thousand pounds gauge pressure.This pressure obviously is far beyond any requirement, as far aspropylene oxide goes, unless there is a reaction of explosive violenceinvolved due to accident. The autoclave was equipped with theconventional devices and openings, such as the variable-speed stirreroperating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer welland thermocouple for mechanical thermometer; emptying outlet; pressuregauge, manual vent line; charge hole for initial reactants; at least oneconnection for introducing the alkylene oxide, such as propylene oxideor ethylene oxide, to the bottom of the autoclave; along with suitabledevices for both cooling and heating the autoclave, such as a coolingjacket, and preferably, coils in addition thereto, with the jacket soarranged that it is suitable for heating with steam or cooling withWater and further equipped with electrical heating devices. Suchautoclaves are, of course, in essence, small-scale replicas of the usualconventional autoclave used in oxyalkylation procedures. In someinstances in exploratory'preparations, an autoclave having a smallercapacity, for instance, approximately 3 /2 liters in one case and about1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, wasachieved by the use of a separate container to hold the alkylene oxidebeing employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the container consists essentially of a laboratorybomb having a capacity of about one-half gallon, or somewhat in excessthereof. In some instances, a larger bomb was used, to wit, one having acapacity of about one gallon. This bomb was equipped, also, with aninlet for charging, and an eductor tube going to the bottom of thecontainer so as to permit discharging of alkylene oxide in the liquidphase to the autoclave. A bomb having a capacity of about 60 pounds wasused. in connection with the 15-gallon autoclave.

Other conventional equipment consists, of course, of the rupture disc,pressure gauge, sight feed glass, thermometer, connection for nitrogenfor pressuring bomb, etc. The bomb was placed on a scale during use. Theconnections between the bomb and the autoclave were flexible stainlesssteel hose or tubing, so that continuous weighings could be made withoutbreaking or making any connections. This applies also to the nitrogenline, which was used to pressure the bomb reservoir. To the extent thatit was required, any other usual conventional procedure or additionwhich provided greater safety was used, of course, such as safety glassprotective screens, etc.

Attention is directed again to what has been said previously in regardto automatic controls which shut 01f the propylene oxide in eventtemperature of reaction passes out of the predetermined range or ifpressure in theautoclave passes out of predetermined range.

With this particular arrangement practical- 1y all oxypropylationsbecome uniform, in that the reaction temperature was held within a fewdegrees of any selected point, for instance, if C. was selected as theoperating temperature, the maximum point would be, at the most, C. or112 C., and. the lower point would be 95 or possibly 98 C. Similarly,the pressure was held at approximately 30 pounds within a 5- poundvariation one Way or the other, but might drop to practically zero,especially where no. solvent such as Xylene is employed. The speed ofreaction was compartively slow, under such conditions, as compared with.oxyalklations at 200 C. Numerous reactions were conducted in which thetime varied from one day (24 hours) up to three days (72 hours), forcompletion of the final member of a series. In some instances, thereaction may take place in considerably less time, i. e., 24 hours orless, as far as a partial oxypropylation is concerned. The minimum timerecorded was about a 4-hour period in a single step. Reactions indicatedas being complete in 7 or 8 hours may have been complete in a lesserperiod of time, in light of the automatic equipment employed. In theaddition of propylene oxide, in the autoclave equipment, as far aspossible, the valves were set so all the propylene oxide, if fedcontinuously, would be added at a rate so that the predetermined amountwould react within the first 5 hours of the 8-hour period or two-thirdsof any shorter period. This meant that if the reaction was interruptedautomatically for a period of time for pressure to drop or temperatureto drop the predetermined amount of oxide would still be added, in mostinstances, well within the predetermined time period. Sometimes wherethe addition was a comparatively small amount in an 8-hour period therewould be an unquestionable speeding up of the reaction, by simplyrepeating the example and using 4, 5 or 6 hours instead of 8 hours.

When operating at a comparatively high temperature, for instance,between to 200 C., an unreacted alkylene oxide such as propylene oxide,makes its presence felt in the increase in pressure or the consistencyof a high pressure, However, at a low enough temperature it may happenthat the propylene oxide goes in as a liquid. If so, and if it remainsunreacted, there is, of course, an inherent danger and appropriate stepsmust be taken to safeguard against this possibility; if need be, asample must be withdrawn and examined for unreacted propylene oxide. Oneobvious procedure, of course, is to oxypropylate at a modestly highertemperature, for instance, at 140 to 150 C. Unreacted oxide affectsdetermination of the acetyl or hydroxyl value of the hydroxylatedcompound obtained.

The higher the molecular weight of the compound, i. e., towards thelatter stages of reaction, the longer the time required to add a givenamount of oxide. One possible explanation is that the molecule, beinglarger, the opportunity for random reaction is decreased. Inversely, thelower the molecular weight, the faster the reaction takes place. Forthis reason, sometimes at least, increasing the concentration of thecatalyst does not appreciably speed up the reaction, particularly whenthe product subjected to oxyalkylation has a comparatively highmolecular weight. However, as has been pointed out previously, operatingat a low pressure and a low temperature, even in large scale operations,as much as a week or ten days time may elapse to obtain some of thehigher molecular weight derivatives from monohydric or dihydricmaterials.

In a number of operations the counterbalance scale or dial scale holdingthe propylene oxide bomb was so set that when the predetermined amountof propylene oxide had passed into the reaction, the scale movementthrough a time operating device was set for either one to two hours, sothat reaction continued for 1 to 3 hours after the final addition of thelast propylene oxide, and thereafter the operation was shut down. Thisparticular device is particularly suitable for use on larger equipmentthan laboratory size autoclaves, to wit, on semi-pilot plant or pilotplant size, as well as on large scale size. The final stirring period isintended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range wascontrolled automatically by either use of cooling water, steam, orelectrical heat, so as to raise or lower the temperature. The pressuringof the propylene oxide into the reaction vessel was also automatic,insofar that the feed stream was set for a slow, continuous run, whichwas shut off in case the pressure passed a predetermined point, aspreviously set out. All the points of design, construction, etc., wereconventional including the gauges, check valves and entire equipment. Asfar as I am aware, at least two firms, and possibly three, specialize inautoclave equipment, such as I have employed in the laboratory, and areprepared to furnish equipment of this same kind. Similarly, pilot plantequipment is available. This point is simply made as a precaution in thedirection of safety. Oxyalkylations, particularly involving ethyleneoxide, glycide, propylene oxide, etc., should not be conducted except inequipment especially designed for the purpose.

Example 1 a The particular automclave employed was one with a capacityof gallons, or on the average of about 125 pounds of reaction mass. Thespeed of the stirrer could be varied from 150 to 350 R. P. M. Theinitial charge was 11 pounds of metaphenylene diamine. Since thisproduct was not particularly alkaline, there was added one pound ofcaustic soda. The reaction pot was flushed out with nitrogen, theautoclave sealed, and the automatic devices adjusted for injecting 87.75pounds of propylene oxide in a 6-hour period. It was injected at therate of about 15 pounds or more, per hour.

10 The pressure regulator was set for a maximum of 35-37 pounds persquare inch. However, in

this particular step, and in all succeeding steps, the pressure nevergot over 37 pounds per square inch. In fact, this meant that the bulk ofthe reaction could take place, and probably did take place, at anappreciably lower pressure. This comparatively low pressure was theresult of the fact that considerable catalyst was added in the initialcharge. All things considered, the propylene oxide was addedcomparatively slowly,

and more important, the selected temperature range was 250-255 F.(moderately higher than the boiling point of water). The initialintroduction of propyleneoxide was not started until the heating deviceshad raised the temperature to a little above the boiling point of water.At the completion of the reaction, a sample was taken and oxypropylationproceeded, as in Example 2a, immediately following.

Example 211 52.5 pounds of reaction mass identified'as 112-1 continued,as in Example 3a, immediately following.

Example 311 49.75 pounds of reaction mass identified as Example 2a,preceding, and equivalent to 2 .99 pounds of the polyamine, 46.49 poundsof propylene oxide, and .27 pound of caustic soda, were subjected toreaction with an additional 35 pounds of propyleneoxide. The conditions,as far as temperature and pressure were concerned, were the same as inthe two preceding examples. The time period was somewhat longer, to wit,7 hours. The propylene oxide was added at the rate of about 6 pounds perhour. The slower rate was probably due to the lower catalyst content. Atthe completion of the reaction part of the reaction mass was withdrawnand the'remainder subjected to a final oxypropylation step, as de-'scribed in Example 4a, immediately following.

Example 4a 52.5 pounds of reaction mass identified as Ex ample 3a,preceding, and equivalent to .1.66 pounds of the polyamine, 50.69 poundsof propylene oxide, and .15 pound of caustic soda, were subjected tofurther oxypropylation with 25 pounds of propylene oxide. The conditionsof reaction, as far as temperature and pressure were concerned, were thesame as in the three preceding examples. the 25 pounds of propyleneoxide was 5 hours. It was added at the rate of about 6 pounds per hour.

What has been said herein is presented'in tabular form in Table I,immediately following, with some added information as to molecularweight and as to solubility of the reaction prod! uct in water, xylene,and kerosene.

The time required to add TABLE 1 Composition Before Composition at End,M. W Max.

by Max. Pres. Ex. Time, No Amine Oxide (llata- Ii linen. imiie gxutle10;??- ir 3;; Hrs,

Amt, Amt, yst, o m m lbs lbs. lbs. Wt. lbs. lbs. lbs.

la; 11. 1. 0 970 11. 0' 87. 75 1. 0 786 250255 35-37 6. 211. 5. 76 45.97 52 1, 785 5. 76 89. 47 52 1, 708 250-255 35-37 4. 35. 2. 99 46. 49 273, 410' 2. 99 81. 49 27 2, 600 250255 35-37 7 4a.- 1. 66, 50. 69 15 5,020 1. 66 75. 69 15. 300 250-255 35-37 Example 1a was soluble in waterbut insoluble in both xylene and kerosene; Example 2a was insoluble inwater, soluble in xylene but insoluble in kerosene; Example 3a wasinsoluble in water, soluble in xylene, and dispersible in kerosene; andExample 4w was insoluble in water but soluble in both xylene andkerosene.

The final product, i. e., at the, end of the oxypropylation step, wasapt to be either a straw color, or sometimes it would have a moredefinite light reddish amber or a distinct dark amber tinge, and attimes, even a deep red amber color. In the later stages the product wasinvariably waterinsoluble and kerosene-soluble. This is characteristicof all the products obtained from the triamine products hereindescribed. Needless to say, if more ethylene oxide radicals wereintroduced into the initial raw material, the initial product is morewater-soluble and one must go to higher molecular weights to producewater-insolubility and kerosene-solubility, for instance, molecularweights such as 8,000 to 10,000 or more on a theoretical basis, and4,000 to 5,000, or even more, on a hydroxyl molecular weight basis. If,however, the initial diamino compound is treated with one or more orperhaps several moles of butylene oxide, then the reverse effect isobtained and it takes less propylene oxide to produce water-insolubilityand kerosene-solubility. These products were, of course, slightlyalkaline, due to the residual caustic soda employed. This would alsobethe case if sodium methylate were used as acatalyst.

Speaking of insolubility in wateror'solubility-in kerosene; suchsolubility test can be made simply by shaking small amounts of thematerials in a test tube withwater, for instance; usin 1% to 5%approximately based on'the amountof water present.

Needless-to say, there is no completeconversionof propylene oxide intothe desired hydroxylated compounds. This is indicated by'the factthatthe theoretical molecular weight, based on a statistical average, isgreater than the molecular weight calculated by usual methods on basisof acetyl or hydroxyl value. Actually, there is no completelysatisfactory method for determining molecular weights of these types ofcompounds with a high degree ofaccuracy when the molecular weightsexceed 2,000. In some instances, the acetylvalue or hydroxyl valueserves as-satisfactorilyas an index to the molecular weight as any otherprocedure, subject to the above-limitations, and especially in thehigher molecular weight range. If any dimculty' is encountered in themanufacture of the esters, as described in Part 2, the stoichiometricalamount of acid or acid compound should, be taken which correspondstotheindicatedacetyl or hydroxyl value. This matter has been discussed in theliterature and-is a matter of common knowledge andzrequires no furtherelaboration. In fact-,it. is. illustrated by'some of the examplesappearing in the patent previously mentioned.

PART 2 As pointed out previously, the present invention is concernedwith acidic esters obtained from the oxypropylated derivatives describedin Part 1, im mediately preceding, and polycarboxy acids, particularlytricarboxy acids like citric and dicarboxy acids such as adipic acid,phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacicacid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconicacid or anhydride, maleic acid. or anhyride adducts, as obtained by theDiels- Alder reaction from products such asmaleic anhyride, andcyclopentadiene. Such acids should, be heat-stable so they arenot'decomposed during; esterification. They may contain as many as 36carbon. atoms, as, for example, the acids obtained by dimerization ofunsaturated fatty acids, unsaturated monocarboxy fatty acids, orunsaturated monocarboxy acids having 18carbon atoms. Refs erence to theacid in hereto appended claims ob-- viously includes the anhydrides orany other obvious equivalents. My preference, however, is to usepolycarboxy acids. having not, over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols, or other hydroxylated compounds, is wellknown. In the present instance the hydroxylated compounds obtained asdescribed in Part 1, preceding, contain nitrogen atoms, which, at themost, are only weakly basic. Thus, there is question as tothe stabilityof any hydrochloride produced, or any. other similar salt produced underconditions of esterification. If salts were formed, then in reality, itwould be the salt that would beconverted into an ester. This iscomparableto, similar reactions involving esterification. oftriethanolamine. However, it is not believed thatthis enters into theinstant compounds derived from phenylene diamine, in light of what has.been said previously.

Needless to say, various compounds may be. used such as the low molalester, the anhydride, the acyl chloride, etc. However, for purpose ofeconomy, it is customary to use either the acid or the anhydride. Aconventional procedure is employed. On a laboratory scale one can employa resin pot of the kind described'in U. S. Patent No. 2,499,370, datedMarch 7, 1950 to De Groote and Keiser, and particularly with one moreopening to permit the use of a porous spreader, if hydrochloric acid gasis to be used as a catalyst. Such device or absorption spreader consistsof minute Alundum thimbles which are connected to a glass tube. One canadd a sulfonic acid, such as paratoluene sulfonic acid as a catalyst.There is some objection to this, because, in some instances, there issome evidence that this acid catalyst tends to decompose or rearrangethe oxypropylated compounds, and particularly likely to do so if theesterification temperature is too high. In the case of polycarboxy acidssuch as diglycollic acid, which is strongly acidic there is no need toadd any catalyst. The use of hydrochloric acid gas has one advantageover paratoluene sulfonic acid, and that is that at the end of thereaction, it can be removed by flushing out with nitrogen, whereas,there is no reasonably convenient means available of removing theparatoluene sulfonic acid or other sulfonic acid employed. Ifhydrochloric acid is employed, one need only pass the gas through at anexceedingly slow rate so as to keep the reaction mass acidic. Only atrace of acid need be present. I have employed hydrochloric acid gas, orthe aqueous acid itself to eliminate the initial basic material. Mypreference, however, is to use no catalyst whatsoever and to insurecomplete dryness of the diol, as described in the final procedure justpreceding Table 2.

The products obtained in Part 1, preceding, may contain a basiccatalyst. As a general procedure, I have added an amount ofhalf-concentrated hydrochloric acid considerably in excess of what isrequired to neutralize the residual catalyst. The mixture is shakenthoroughly and allowed to stand overnight. It is then filtered andrefluxed with the xylene present until the water can be separated in aphase-separating trap. As soon as the product is substantially free fromwater, the distillation stops. This preliminary step can be carried outin the flask to be used for esterification. If there is any furtherdeposition of sodium chloride during the reflux stage, needless to say,a second filtration may be required. In any event, the neutral orslightly acidic solution of the oxypropylated derivatives described inPart 1 is then diluted further with sufficient xylene, decalin,petroleum solvent, or the like, so that one has obtained approximately a40% solution. To this solution there is added a polycarboxylatedreactant, as previously described, such as phthalic anhydride, succinicacid or anhydride, diglycollic acid, etc. The mixture is refluxed untilesterification is complete, as indicated, by elimination of water ordrop in carboxyl value. Needless to say, if one produces a half esterfrom an anhydride such as phthalic anhydride, no water is eliminated.However, if it is obtained from diglycollic acid,'for example, water iseliminated. All such procedures are conventional and have been sothoroughly described in the literature that further consideration willbe limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any,can be employed. For example, the oxyalkylation can be conducted inabsence of a solvent or the solvent removed after oxypropylation. Suchoxypropylation end product can then be acidified with just enoughconcentrated hydrochloric acid to just neutralize the residual basiccatalyst. To this product one can then add a small amount of anhydroussodium sulfate (sufficient in quantity to take up any water that ispresent) and then subject the mass to centrifugal force so as toeliminate the hydrated sodium sulfate and probably the sodium chlorideformed. The clear, somewhat viscous, straw-colored to dark amber liquidso obtained may contain a small amount of sodium sulfate or sodiumchloride, but, in any event, is perfectly acceptable for esterificationin the manner described.

It is to be pointed out that the products here described are notpolyesters in'the sense that there is a plurality of both diaminoradicals and and acid radicals; the product is characterized by havingonly one diamino radical.

In some instances I have found that in spite of the dehydration methodsemployed above, that a mere trace of water still comes through and thatthis mere trace of water certainly interferes with the acetyl orhydroxyl value determination, at least when a number of conventionalprocedures are used and may retard esterification, particularly wherethere is no sulfonic acid or hydrochloric acid present as a catalyst.Therefore, I have preferred to use the following procedure: I haveemployed about 200 grams of the polyhydroxylated compound, as describedin Part 1, preceding; I have added about 60 grams of benzene, and thenrefluxed this mixture in the glass resin pot, using a phase-separatingtrap until the benzene carried out all the water present as water ofsolution or the equivalent. Ordinarily, this refluxing temperature isapt to be in the neighborhood of 130 to possibly 150 C. When all thiswater or moisture has been removed, I also withdraw approximately 20grams or a little less benzene and then add the required amount of thecarboxy reactant and also about 150 grams of a high boiling aromaticpetroleum solvent. These solvents are sold by various oil refineries,and, as far as solvent effect, act as if they were almost completelyaromatic in character. Typical distillation data in the particular typeI have employed and found very satisfactory is the following:

I. B. P., 142 C. 50 ml., 242 C. 5 ml., 200 C. 55 ml., 244 C. 10 ml., 209C. 60 ml., 248 C. 15 ml., 215 C. ml., 252 C. 20 ml., 216 C. ml., 252 C.25 ml., 220 C. ml., 260 C. 30 ml., 225 C. ml., 264 C. 35 ml., 230 C.ml., 270 C. 40 ml., 234 C. ml., 280 C. 45 ml., 237 C. ml., 307 C.

After this material is added, refluxing is continued, and of course, isat a higher temperature, to wit, about to C. If the carboxy reactant isan anhydride, needless to say, no water of reaction appears; if thecarboxy reactant is an acid, water of reaction should appear and shouldbe eliminated at the above reaction temperature. If it is noteliminated, I simply separate out another 10 or 20 cc. of benzene bymeans of the phase-separating trap, and thus, raise the temperature toor C., or even to 200 C., if need be. My preference is not to go above200 C.

The use of such solvent is extremely satisfactory, provided one does notattempt to remove the solvent subsequently except by vacuumdistillation, and provided there is no objection to a little residue.Actually, when these materials are used for a purpose such asdemulsification, the solvent might just as well be allowed to remain. Ifthe solvent is to be removed by distillation, and particularly vacuumdistillation, then the high boiling aromatic petroleum solvent mightwellbe replaced by some more expensive solvent, such as decalin, or analkylated decalin, which has a rather definite or close range boilingpoint. The removal of the solvent, of course, is purely a conventionalprocedure and requires no elaboration.

However, in this series of derivatives involving phenylene diamine, Ihave preferred to use xylene, for the reason that it could be removedcompletely by distillation, particularly vacuum :3, 62.6,,:923 15 .16distillation. As a result, in the data-immediately by filtering.Everything else zbeing equal ,as the following, the only solvent thatappears is xylene. size of the .molecule increases and the reactive Anyone of a numberzof other suitable solvents, hydroxyl radical representsa, smaller fraction however, would be equally satisfactory, els -pointedof the entire molecule, more ,difi'iculty is inout previously. 5 volvedin obtaining complete esterfication.

TABLE 2 Ex. Theo. 1 Mol. Amt.- of NEx. I N Ho. Itl. T1513? Afitual BWt.dg? Posy- 0- 0. yyase car oxy Acid droxy of gfifgg droxyl on gg dPolycarbon Reacta'nt React- Ester Cmpd. H. C. H 0 Value Actual p antgrs.) (grs 970 174 214 786 135 Diglycollic Acid v94. 6 970 174 214 786;186 Aconitlc Acid- 123.0 070 174 214 786 202 Oxalic Acid .970 070 174214 706 187 Ththalic Anhydride. 106.0 970 174 214 786 279 MaleicAnhydride 104.0 970 174 214 786 262 Oitraconic Anhydride... 112. 0 1,785 126 131. 1, 708 209 DiglycollicAcid 65. 5 1, 785 126 131.5 1, 703213 Aconitic Acid 87.0 1, 735 126 131.5 1, 703 209 Oxalic Acid .61.:5 1,785 126 131. 5 1, 703 222 Pllthalic Anhydrlde. 77. 0 1, 735 126 131.5 1,703 209 Maleic Anhydride 43.0 1, 785 126 131. 5 l, 708 202 .CitraconicAnhydrido... 53.0 3, 410 66 86. 5 2, 600 202 Diglycolllc Acid 41. 5 3,410 66 86. 5 2, 600 202 ACOHifiC Acid 54. 0 3, 410 66 86. 5 2, 600 202015116 Acid 39. 2 3,410 66 86.5 2,600 205 Phthalic 111111 46.6 3,410 6636.5 2,600 109 ll/laleic Anhydride. 30.0 3, 410 66 86.5 2, 600 19sCitraconic Anhydride 34. 0 5,020 44. 9 68 3, 300 109 Diglycollic Acid32. 3 5,020 44.9 68 3,300 200 Aconitic Acid 42. 0 5,020 44. 9 68 3, 300202 Oxalic Acid 30.3 5, 020 44. 9 68 300 212 Phthalic Anhydrlde 37.05,.020 44.9 68 3. 300 200 Maleic Anhydride 23. 7 5, 020 44. 9 .68 3,300193 Cltraconic Anhydride 27.0

TABLE 3 Even under the most carefully controlled conditions ofoxypropylation involving comparatively Amt gi f Time of Water lowtemperature andlong time of reaction, there Solvent 5 en Esterifica- Out(gm) tion Temp., mm (hrs) (cc) ale for med certain compounds whosecomposition is still obscure. Such side reaction products can contributea substantial proportion of the final Z cogeneric reaction mixture.Various-suggestions 5 14s 4 have been made as to the nature of thesecomggg ii; 'i pounds, such as being cyclic polymers of propyl- 374 160 5ene oxide, dehydration products with the appear ance of a vinyl radical,or isomers of propylene 243 142 2 oxide or derivatives thereof, 1. e.,of an aldehyde, m g ketone, or allyl alcohol. In some instances, an 255144 3 attempt to react the stoichiometric amount of a ti? i polycarboxyacid with the oxypropylated derivaggg tives results in an excess of thecarboxylated 3 M8 4 reactant for the reason that apparently under 4g 4conditions of reaction less'reactive hydroxyl radi- 238 cals are presentthan indicated by the hydroxyl value. Under such circumstances there issim- 151 ply a residue of the carboxylic reactant which 226 148 can beremoved by filtration, or, if desired, the

The procedure for manufacturing the esters has been illustratedby'preceding examples. If, for any reason, reaction does not takeplacein a manner that is acceptable, attention should be directed to thefollowing details:

(a) Recheck the hydroxyl or acetyl value of the oxypropylated derivativeand use of stoichiometrically equivalent amount of acid;

(b) If the reaction does not proceed with reasonable speed either raisethe temperature indicated .orelse extend the period of time .up .to 12-or 15 hours, if need be;

(c) If necessary, use of paratoluene sulfonic acid, or some other acidas a catalyst, provided that the hydroxylated compound .is not basic;

(d) If the esterification does not produce a clear product, a checkshould be made to .see if an inorganic salt such as sodium chloride orsodium sulfate is not precipitating out.

Such salt should be eliminated, at least for explorationexperimentation, and can be removed esterification procedure can berepeated, using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value by conventional procedureleaves much to be desired, due either to the cogeneric materialspreviously referred to, or for that matter, the presence of anyinorganic salts or propylene oxide. Obviously, this oxide should beeliminated.

The solvent employed, if any, can be removed from the finished ester bydistillation, and .particularly vacuum distillation. The final productsor liquids are generally straw to dark amber or reddish amber in color,and show moderate viscosity. They can be bleached with bleaching clays,filtering chars, and the like. However, for purpose of demulsificationor the like, color is not a factor and decolorization is not justified.

In the above instances I have permitted the solvents to remain present,in the final reaction mass. In other instances, I have followed thesame procedure, using decalin or a mixture of decalin, or benzene in thesame manner and ultimately removed all the solvents byvacuum'distillation. Appearances of the final products are much the sameas the diols before esterification, and in some instances, were somewhatdarker in color and had a reddish cast and perhaps were somewhat moreviscous.

' It is unnecessary to point out, of course, that what has been saidherein is the same, regardless of whether the initial material is apolyhydroxylated compound or a compound containing a plurality ofhydrogen atoms attached to nitrogen.

Y PART 3 In the hereto appended claims the demulsifying agent isdescribed as an ester obtained from a polyhydroxylated material having aleast 2 reactive hydrogens. If one were concerned with amonohydroxylated material or a dihydroxylated material, one might beable to write a formula which, in essence, would represent theparticular product. However, in a more highly hydroxylated material theproblem becomes increasingly more difiicult for reasons which havealready been indicated in connection with oxypropylation and which canbe examined by merely considering for the moment a monohydroxylatedmaterial.

Oxypropylation involves the same sort of variations as appear inpreparing high molal polypropylene glycols. Propylene glycol has asecondary alcoholic radical and a primary alcohol radical. Obviously,then, polypropylene glycols could be obtained, at least theoretically,in which two secondary alcoholic groups are united or a secondaryalcohol group is united to a primary alcohol group, etherization beinginvolved, of course, in each instance. Needless to say, the samesituation applies when one has oxypropylated and polyhydric materialshaving 4 or more hydroxyls, or the obvious equivalent.

Usually no efiort is made to differentiate between oxypropylation takingplace, for example, at the primary alcohol unit radical or the secondaryalcohol radical. Actually, when such products are obtained, such as ahigh molal polypropylene glycol or the products obtained in the mannerherein described one does not obtain a single derivative such as HO(RO)11H or (RO)nH, in which n has one and only one value, for instance, 14,15, or 16, or the like. Rather, one obtains a cogeneric mixture ofclosely related or touching homologues. These materials invariably havehigh molecular weights and cannot be separated from one another by anyknown procedure Without decomposition. The properties of such mixturerepresent the contribution. of the various individual members of themixture. On a statistical basis, of course, it can be appropriatelyspecified. For practical purposes, one need only consider theoxypropylation of a monohydric alcohol, because, in essence, this issubstantially the mechanism involved. Even in such instances where oneis concerned with a monohydric reactant, one cannot draw a singleformula and say that by following such procedure, one can readily obtain80% or 90% or 160% of such compound. However, in the case of at leastmonohydric initial reactants, one can readily draw the formulae of alarge number of compounds which appear in some of the probable mixtures,or can be prepared as components and mixtures which are manufacturedconventionally.

Simply by way of illustration, reference is made to the co-pendingapplication of De Groote, Wirtel and Pettin'gill, Serial No. 109,791,filed 18 August 11, 1949 (now Patent 2,549,434, granted April 17, 1951).

However, momentarily referring again to a monohydric initial reactant,it is obvious that if one selects any such simple hydroxylated compoundand subjects such compound to oxyalkylation, such as oxyethylation, oroxypropylation, it becomes obvious that one is really producing apolymer of the alkylene oxide except for the terminal group. This isparticularly true where the amount of oxide added is comparativelylarge, for instance, 10, 20, 30, 40, or 50 units. If such compound issubjected to oxyethylation so as to introduce 30 units of ethyleneoxide, it is well known that one does not obtain a single constituent,which, for the sake of convenience, may be indicated as RO(C2H4O)30H.Instead, one obtains a cogeneric mixture of closely related homologues,in which the formula may be shown as the following, RO(C2II4O)nH,wherein, n, as far as the statistical average goes, is 30, but theindividual members present in significant amount may vary from instanceswhere n has a Value of 25, and perhaps less, to a point where 12 mayrepresent 35 or more. Such mixture is, as stated, a cogeneric, closelyrelated series of touching homologous compounds. Considerableinvestigation has been made in regard to the distribution curves forlinear polymers. Attention is directed to the article entitledFundamental Principles of Condensation Polymerization, by Flory, whichappeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematical examination, of indicating the exact proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without difficulty, it is necessary to resort to some other methodof description, or else consider the value of n, in formulae such asthose which have appeared previously and which appear in the claims, asrepresenting both individual constituents in which n has a singledefinite value, and also with the understanding that n represents theaverage statistical value, based on the assumption of completeness ofreaction.

This may be illustrated as follows: Assume that in any particularexample the molal ratio of propylene oxide per hydroxyl is 15 to 1. In ageneric formula 15 to 1 could be 10, 20, or some other amount andindicated by n. Referring to this specific case actually one obtainsproducts in which n probably varies from 10 to 20, perhaps even further.The average value, however, is 15, assuming, as previously stated, thatthe reaction is complete. The product described by the formula is bestdescribed also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines hereindescribed is that in the initial stage they are substantially allwatersoluhle, for instance, up to a molecular weight of 1,590 orthereabouts. Actually, such molecular weight represents a mixture ofsome higher molecular weight materials and some lower molecular weightmaterials. The higher ones are probably water-insoluble. The product maytend to emulsify or disperse somewhat because some of the constituents,being a cogeneric mixture, are water-soluble but the bulk are insoluble.Thus, one gets emulsifiability or dispersibility as noted. Such productsare invariably xylene-soluble, regardless of whether the originalreactants were or not. Reference is made to what has been saidpreviously in regard to kerosene-solubility. For example, when thetheoretical molecular weight gets somewhere past 4,000, or atapproximately 5,000, the product is kerosene-soluble andwater-insoluble. These kerosene-soluble oxyalky-lation products are mostdesirable for preparing the esters. I have prepared hydroxylatedcompounds not only up to the theoretical molecular weight shownpreviously, i. e., about 5,000, but also some which were twice thishigh. I have prepared them, not only from phenylenediamine, but alsofrom oxyethylated or oxybutylated derivatives previously referred to.The exact composition is open to question, for reasons which are commonto all oxyalkylation. It is interesting to note, however, that themolecular weights based on hydroxyl determinations at this point wereconsiderably less, in the neighborhood of a third ,or a fourth of thevalue at maximum point. Referring again to previous data, it is to benoted, however, that over the range shown of kerosene-solubility, thehydroxyl molecular weight has invariably stayed at two-thirds orfive-.eighths of the theoretical molecular weight.

It becomes obvious, when carboxylic esters are prepared from such highmolecular weight materials, that the ultimate esterification productagain must be a cogeneric mixture. Likewise, it is obvious that thecontribution to the total molecular weight made by the polycarboxy acidis small. By the same token, one would expect the effectiveness of thedemulsifier to be comparable to the unesterified hydroxylated material.Remarkably enough, in many instances the product is distinctly better.

PART 4 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablesolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols,particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol,denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, .octylalcohol, etc may be employed as diluents. Miscellaneous solvents, suchas pine oil, carbon tetrachloride, sulfur dioxide extract obtained inthe refining of petroleum, 4

etc., may be employed as diluents. Similarly, the material or materialsemployed as the demulsifying agent of my process may be admixed with oneor more of uhe solvents customarily used in connection with conventionaldemulsifying agents. Moreover, said material or materials may be usedalone, or in admixture with other suitable wellknoyvn classes ofdemulsifying agents.

It is well known that conventional demulsifying agents may be used in awater-soluble form, or in an oil-soluble form, or in a form exhibitingboth oiland water-solubility. Sometimes they may be used in a form whichexhibits relatively limited oil-solubility. However, since such reagentsare frequently used in a ratio of 1 to 10,000

or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000, asin desalting practice, such as apparent insolubility in oil and water isnot sign ficant, because said reagents undoubtedly have solubilityWithin such concentrations. This same 20 fact is true in regard .to thematerial or materials employed as the demulsifying agent of my p rocess.

In practising my process for resolving petroleum emulsions of thewater-in-oil type, a treating agent or demulsifying agent of the kindabove described is brought into contact with or caused to act upon theemulsion to be treated, in any of the various apparatus now generallyused to resolve or break petroleum emulsions with a chemical reagent,the above procedure being used alone or in combination with otherdemulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. In this procedure the emulsion is admixed with thedemulsifier, for example, by agitating the tank of emulsion and slowlydripping demulsifierinto the emulsion. In some cases, mixing is achievedby heating the emulsion while dripping in the demulsifier, dependingupon the convection currents ,in the emulsion to produce satisfactoryadmixture. In a third modification of this typeof treatment, acirculating pump withdraws emulsion from, e. g., the bottom of the tank,and reintroduces it into the top of the tank, the demulsifier beingadded, for example, at the suction side ofsaid circulating pump.

In a second type of treating procedure, the demulsifier is introducedinto the well vfluids at the well-head or at some point between thewellhead and the final oil storage tank, by means of an adjustableproportioning mechanism or proportioning pump. Ordinarily, the flow offluids through the subsequent lines and fittings suffices to produce thedesired degree of mixing of demulsifier and emulsion, although, in someinstances, additional mixing devices may be introduced into the flowsystem. In this general procedure, the system may include variousmechanical devices for withdrawing free Water, separating entrainedwater, or accomplishing quiescent settling of the chemicalized emulsion.Heating devices may likewise be incorporated in any of the treatingprocedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsionis to introduce the demulsifier either periodically or continuously indiluted or undiluted ,form into the well and to allow it to come to thesurface with the well fluids, and then to flow the chemicalized emulsionthrough any desirable surface equipment, such as employed in the othertreating procedures. This particular type of application is decidedlyuseful when the demulsifier is used in connection with acidification ofcalcareous oil-bearing strata, especially if suspended in ,or dissolvedin the acid employed for acidification,

In all cases, it will be apparent ,from the foregoing description, thebroad process consists simply in introducing a relatively smallproportion of demulsifier into a relatively large proportion ofemulsion, admixing the chemical and emulsion either through natural newor through special apparatus, with or without the application of heat,and allowing the mixture to stand quiescent until the undesirable watercontent of the emulsion separates and settles from the same.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted orundiluted) is placed at the of fluid produced in 4 to 24 hours (500barrels to 2,000 barrels capacity), and in which there is aperpendicular conduit from the top of the tank to almost the very bottomso as to permit the incoming fluids to pass from the top of the settlingtank to the bottom, so that such incoming fluids do not disturbstratification which takes place during the course of demulsification.The settling tank has two outlets, one being below the water level todrain ofi the water resulting from demulsification or accompanying theemulsion as free water, the other being an oil outlet at the top topermit the passage of dehydrated oil to a second tank, being a storagetank, which holds pipeline or dehydrated oil. If desired, the conduit orpipe which serves to carry the fluids from the well to the settling tankmay include a section of pipe with baffles to serve as a mixer, toinsure thorough distribution of the demulsifier throughout the fluids,or a heater for raising the temperature of the fluids to some convenienttemperature, for instance, 120 to 160 F" or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as tofeed a comparatively. large ratio of demulsifier, for instance, 1:5,000.

As soon as a complete break" or satisfactory demulsification isobtained, the pump is regulated until experience shows that the amountof demulsifier being added is just suflicient to produce clean ordehydrated oil. The amount being L fed at such stage is usually1110,000, 1:15,000, 1:20,000, or the like.

In many instances, the oxyalkylated products herein specified asdemulsifiers can be conveniently used without dilution. However, aspreviously noted, they may be diluted as desired with any suitablesolvent. For instance, by mixing 75 parts, by weight, of the product ofExample 13b with 15 parts, by weight, of Xylene and 10 parts, by weight,lent demulsifier is obtained. Selection of the solvent will vary,depending upon the solubility characteristics of the oxyalkylatedproduct, and of course, will be dictated, in part, by economicconsiderations, i. e., cost.

As noted above, the products herein described may be used not only indiluted form, but also may be used admixed with some other chemicaldemulsifier. combination is the following:

Oxyalkylated derivative, for example, the product of Example 131), 20%;

A cyclohexylamine salt of a polypropylated naphthalene monosulfonicacid, 24%;

An ammonium salt of a polypropylated naphthalene monosulfonic acid, 24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%;

A high-boiling aromatic petroleum solvent, 1

Isopropyl alcohol, 5%.

The above proportions are all weight percents.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

of isopropyl alcohol, an excel- A mixture which illustrates such 1. Aprocess for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) A polycarboxy acid; and (B)High molal oxypropylation derivatives of monomeric diamino compounds,with the proviso that (a) The initial diamino reactant be free from anyradical having at least 8 uninterrupted carbon atoms; (1)) The initialdiamino reactant have a molecular weight of not over 800 and at least aplurality of reactive hydrogen atoms; (0) The initial diamino reactantmust be water-soluble; (d) The oxypropylation end product must bewater-insoluble, and kerosene soluble; (e) The oxypropylation endproduct be within the molecular weight range of 2,000 to 30,000 on anaverage statistical basis; (I) The solubility characteristics of the.oxypropylation end product in respect to water and kerosene must besubstantially the result of the oxypropylation step; (g) The ratio ofpropylene oxide per initial reactive hydrogen atom must be within therange of '7 to 70; (h) The initial diamino reactant must represent notmore than 20%, by weight, of the oxypropylation end product on astatistical basis; (1') The preceding provisos are based on theassumption of complete reaction involving the propylene oxide andinitial diamino reactant; (9) The nitrogen atoms are linked by aphenylene ring, and with the final proviso that the ratio of (A) to (B)be one mole of (A) for each reactive hydrogen atom present in (B).

2. A process for breaking petroleum emulsions of the Water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) A polycarboxy acid; and (B)High molal oxypropylation derivatives of monomeric diamino compounds,with the proviso that (a) The initial diamino reactant be free from anyradical having at least 8 uninterrupted carbon atoms; (12) The initialdiamino reactant having a molecular weight of not over 800 and at leasta plurality of reactive hydrogen atoms; (0) The initial diamino reactantmust be water-soluble; (d) The oxypropylation end product must bewater-soluble, and kerosene-soluble; oxypropylation end product bewithin the molecular weight range of 2,000 to 30,000 on an averagestatistical basis; (f) The solubility characteristics of theoxypropylation end product in respect to water and kerosene must besubstantially the result of the oxypropylation step; (g) The ratio ofpropylene oxide per initial reactive hydrogen atom must be within therange of '7 to 70; (h) The initial diamino reactant must represent notmore than 20%, by weight, of the oxypropylation end product on astatistical basis; (1) The preceding provisos are based on theassumption of complete reaction involving the propylene oxide andinitial diamino reactant; (9') The nitrogen atoms are linked by aphenylene ring; (it) At least one of the nitrogen atoms be basic, andwith the final proviso that the ratio of (A) to (B) be one mole of (A)for each reactive hydrogen atom present in (B).

(e) The ,3. A process i101 breakin pet oleum emulsions of thewater-imoil type, characterized by subjecting the emulsion to the actionof a .demulsifier including hydrophile synthetic products; saidhydrophile synthetic products being ,a cogeneric mixture selected fromthe class consisting of acidic fractional esters, acidic ester salts,and acidic amido derivatives obtained by reaction between (A) Apolycarboxy acid, and (B) High molal oxypropylation derivatives ofmonomeric diamino compounds, with the proviso that (a) The initialdiamino reactant be free from any radical having at least 8uninterrupted carbon atoms; (b) The initial diamino reactant have amolecular Weight of not over 800 and at least a plurality of reactivehydrogen atoms; (0) The initial diamino reactant must be water-soluble;(d) The oxypropylation end product must be water-insoluble, andkerosene-soluble; (e) The oxypropylation end product be Within themolecular weight range of 2,000 to 30,000 on an average statisticalbasis; (,r') The solubility characteristics of the oxypropylation endproduct in respect to water and kerosene must be substantially theresult of the oxypropylation step; (a) The ratio of propylene oxide perinitial reactive hydrogen atom must be within the range of 7 to '70;,(h) The initial diamino reactant must represent not more than 20%, byweight, of the oxypropylation end product on a statistical basis; (2)The preceding provisos are based on the assumption of complete reactioninvolving the propylene oxide and initial diamino reactant; (9') Thenitrogen atoms are linked by a phenylene ring; (k) That both nitrogenatoms be basic; and with the final proviso that the ratio of (A) to (B)be one mole of (A) for each reactive hydrogen atom present in (B).

4. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) A polycarboxy acid freefrom any radical having more than 8 uninterrupted carbon atoms in asingle group, and (B) High molal oxypropylation derivatives of monomericdiamino compounds, with the proviso that (a) The initial diaminoreactant be free from any radical hav ing at least 8 uninterruptedcarbon atoms; (1)) The initial diamino reactant have a molecular weightof not over 800 and at least a plurality of reactive hydrogen atoms; (c)The initial diamino reactant must be water-soluble; (d) Theoxypropylation end product must be water-insoluble, andkerosene-soluble; (e) The oxypropylation end product be within themolecular weight range of 2,000 to 30,000 on an average statisticalbasis; (1) The solubility characteristics of the oxypropylation endproduct in respect to water and kerosene must be substantially theresult of the oxypropylation step; (9) The ratio of propylene oxide perinitial reactive hydrogen atom must be Within the range of 7 to 70; (h)The initial diamino reactant must represent not more than 20%, byweight, of the oxypropylation end product on a statistical basis; (i)The preceding provisos are based on the assumption of complete reactioninvolving the propylene oxide and initial diamino reactant; (9') Thenitrogen atoms are linked by a phenylene ring; (k) That both nitrogenatoms be basic; and with the final 24 proviso that the cratioof ,(A) to(B) beone mole of (A) for ,each reactive hydrogen atom present in ,(B),

.5. Aprocess for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) A dicarboxy acid free ,fromany radical having more than 8 uninterrupted carbon atoms in a singlegroup, and (B) High molal oxypropylation derivatives of monomericdiamino compounds, with the proviso that (a) The initial diaminoreactant be free from any radical having at least 8 uninterrupted carbonatoms; .(b) The initial diamino reactanthaving a molecular weight of not,over 800 and at least a plurality of reactive hydrogen atoms; (0) Theinitial diamino reactant must be water-soluble; (d) The oxypropylationend product must be water-insoluble, and kerosene-soluble; (e) Theoxypropylation end product be within the molecular weight range of 2,000to 30,000 on an average statistical basis; (f) The solubilitycharacteristics of the oxypropylation end product in respect to waterand herosene must be substantially the result of the .oxypropylationstep; (9) The ratio of propylene oxide per initial reactive hydrogenatom must be Within the range of 7 to '70; (h) The initial diaminoreactant must represent not more than 20%, by weight, of theoxypropylation end product on a statistical basis; (2') The precedingprovisos are based on the assumption of complete reaction involving thepropylene oxide and initial diamino reactant; .(a') The nitrogen atomsare linked by a phenylene ring; (is) That both nitrogen atoms be basic;and with the final proviso that the ratio of (A) to (B) be one mole of(A) for each reactive hydrogen atom present in (B) 6. A process forbreaking petroleum emulsions of the water-in-oil type, characterized bysubjecting the emulsion to the action of a demulsifier includinghydrophile synthetic products; said hydrophile synthetic products beinga cogeneric mixture selected from the class consisting of acidicfractional esters, acidic ester salts, and acidic amido derivativesobtained by reaction between (A) A dicarboxy acid free from any radicalhaving more than 8 uninterrupted carbon atoms in a single group, and (B)High molal oxypropylation derivatives of metaphenylenediamine, with theproviso that (a) The oxypropylation end product must be water-insolubleand kerosene-soluble; (b) The oxypro pylation end product be within themolecular weight range of 2,000 to 30,000 on an average statisticalbasis; (0) The solubility characteristics of the oxypropylation endproduct in respect to water and kerosene must be substantially theresult of the oxypropylation step; (d) The ratio of propylene oxide perinitial reactive hydrogen atom must be within the range of 7 to 70; (e)The initial diamino reactant must represent not more than 20%, byweight, of the oxypropylation end product on a statistical basis; (f)The preceding provisos are based on the assumption of complete reactioninvolving the-propylene oxide and initial diamino reactant; and with thefinal proviso that the ratio of (A) to (B) be one mole of (A) for eachreactive hydrogen atom present in (B).

25 26 7. The process of claim 6, wherein the dicarboxy acid isdiglycollic acid. EEFEBENCES The roc c r;1 Wherem the The followingreferences are of record in the carboxy acid 15 malelc acld. m gf thi tnt;

9. The process of claim 6, wherein the dicar- 5 boxy acid is phthalicacid. UNITED STATES PATENTS 10. The process of claim 6, wherein thedicar- Number Name Date boxy acid is citraconic acid. 2,243,329 DeGroote et a1. May 27, 1941 11. The process of claim 6, wherein thedicar- 2,295,169 e GrOOte e al- Sept. 8, 1942 boxy acid is succinicacid. 10 2,562,878 Blair Aug. 7, 1951 his MELVIN X DE GROOTE.

mark

Witnesses to mark:

W. C. ADAMS, 15 I. 6. DE GROOTE.

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE,CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETICPRODUCTS BEING A COGENERIC MIXTURE SELECTED FROM THE CLASS CONSISTING OFACIDIC FRACTIONAL ESTERS, ACIDIC ESTER SALTS, AND ACIDIC AMIDODERIVATIVES OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID; AND (B)HIGH MOLAL OXYPROPYLATION DERIVATIVES OF MONOMERIC DIAMINO COMPOUNDS,WITH THE PROVISO THAT (A) THE INITIAL DIAMINO REACTANT BE FREE FROM ANYRADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (B) THE INITIALDIAMINO REACTANT HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST APLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE INITIAL DIAMINO REACTANTMUST BE WATER-SOLUBLE; (D) THE OXYPROPYLATION END PRODUCT MUST BEWATER-INSOLUBLE, AND KEROSENE SOLUBLE; (E) THE OXYPROPYLATION ENDPRODUCT BE WITHIN THE MOLECULAR WEIGHT RANGE OF 2,000 TO 30,000 ON ANAVERAGE STATISTICAL BASIS; (F) THE SOLUBILITY CHARACTERISTICS OF THEOXYPROPYLATION END PRODUCT IN RESPECT TO WATER AND KEROSENE MUST BESUBSTANTIALLY THE RESULT OF THE OXYPROPYLATION STEP; (G) THE RATIO OFPROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM MUST BE WITHIN THERANGE OF 7 TO 70; (H) THE INITIAL DIAMINO REACTANT MUST REPRESENT NORMORE THAN 20%, BY WEIGHT, OF THE OXYPROPYLATION END PRODUCT ON ASTATISTICAL BASIS; (I) THE PRECEDING PROVISOS ARE BASED ON THEASSUMPTION OF COMPLETE REACTION INVOLVING THE PROPYLENE OXIDE ANDINITIAL DIAMINO REACTANT; (J) THE NITROGEN ATOMS ARE LINKED BY APHENYLENE RING, AND WITH THE FINAL PROVISO THAT THE RATIO OF (A) TO (B)BE ONE MOLE OF (A) FOR EACH REACTIVE HYDROGEN ATOM PRESENT IN (B).